Modal Verbs and Possibility
Understand and use modal verbs (can, may, must, might, shall, will, could, should, would) and modal adverbs (perhaps, surely, certainly) to indicate degrees of possibility, necessity, and permission
What a learner can do afterwards
- Select a modal verb to express certainty, probability, or possibility in a sentence, e.g. 'It will rain' vs 'It might rain' vs 'It could rain'
- Replace a modal verb with a modal adverb to achieve a similar effect, e.g. 'He might come' → 'Perhaps he will come'
- Distinguish between modals expressing permission (may, can), obligation (must, should), and possibility (might, could) in context
1 · Read
Modal verbs are small helper words like can, may, must, might, could, should, would, shall, and will. They sit before another verb and change how sure, allowed, or needed something is.
Zara checks the sky and says three things. "It will rain" means she is sure. "It might rain" means she thinks it is possible. "It could rain" also means possible, but she still is not certain either way.
A school sign says, "Students may leave early on Fridays." That means students are allowed to leave, but do not have to. Another sign says, "Students must wear a badge." That means wearing a badge is required.
Modal verbs can also give advice or offer an idea. 'Should' gives advice: 'You should rest after a long run.' 'Could' offers an idea: 'We could try the new bakery.' 'Shall we' offers to do something together: 'Shall we sit by the window?' Advice is a good idea, not a strict rule like 'must'.
Add 'not' to a modal verb to flip its meaning. 'You must not feed the birds' is a rule against feeding them. 'It can't be midnight' says midnight is not possible. Modal adverbs have strengths too: 'perhaps' is unsure, while 'surely' and 'certainly' are almost completely sure.
You can often swap a modal verb for a modal adverb and keep the same meaning. "He might come" becomes "Perhaps he will come."
Modal verbs and modal adverbs both show how sure, allowed, or required something is, so choose the one that matches what you mean.
2 · Watch
Take it off screen
Where it sits
Where this leads
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